title: Role of metabolic factors in the association between osteocalcin and testosterone in Chinese men.
abstract: OBJECTIVE
  Osteocalcin can regulate energy metabolism and increase testosterone production. Although previous studies have shown the positive association between osteocalcin and testosterone, the effect of metabolic factors in the association is unclear.
  
  
  METHODS
  Osteocalcin, testosterone, and metabolic factors were accessed in 2400 men aged 20 to 69 years, who participated in the population-based Fangchenggang Area Male Health and Examination Survey in Guangxi province of China from September 2009 to December 2009.
  
  
  METHODS
  Metabolic syndrome was defined based on the updated report of National Cholesterol Education Program Adult Treatment Panel III criteria. Serum total osteocalcin, total testosterone (TT), and sex hormone binding globulin (SHBG) were measured, whereas free testosterone (FT) and bioavailable testosterone (BT) were calculated based on Vermeulen's formula. The multivariable linear regression analysis was used.
  
  
  RESULTS
  Osteocalcin was positively associated with TT, FT, and BT in the unadjusted model (all P < .001). After adjusting for age, the positive association between osteocalcin and TT remained statistically significant (β = .17, 95% confidence interval = 0.14-0.20) and was not attenuated in each MetS subgroup including hypertriglyceridemia, hyperglycemia, elevated blood pressure, and low high-density lipoprotein cholesterol, while in the group of central obesity (waist circumstance ≥90 cm), the association appeared significantly stronger (β = 0.21, 95% confidence interval = 0.12-0.30). After further adjusting for SHBG, osteocalcin was positively associated with TT, FT, and BT in men with central obesity or men with any two MetS components (all P < .05).
  
  
  CONCLUSIONS
  Serum total osteocalcin is positively associated with testosterone, which is probably modified by SHBG and central obesity.
authors.affiliation: Institute of Urology and Nephrology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Liao
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Guo
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Yu
authors.forename: Guijian
authors.initials: G
authors.lastname: Pang
authors.forename: Shijun
authors.initials: S
authors.lastname: Zhang
authors.forename: Jianling
authors.initials: J
authors.lastname: Li
authors.forename: Aihua
authors.initials: A
authors.lastname: Tan
authors.forename: Yong
authors.initials: Y
authors.lastname: Gao
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Yang
authors.forename: Haiying
authors.initials: H
authors.lastname: Zhang
authors.forename: Xue
authors.initials: X
authors.lastname: Qin
authors.forename: Linjian
authors.initials: L
authors.lastname: Mo
authors.forename: Zheng
authors.initials: Z
authors.lastname: Lu
authors.forename: Chunlei
authors.initials: C
authors.lastname: Wu
authors.forename: Zengnan
authors.initials: Z
authors.lastname: Mo
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D003430:Cross-Sectional Studies; D006801:Humans; D016014:Linear Models; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood*; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D015675:Osteocalcin / Q000097:blood* / Q000502:physiology; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D013739:Testosterone / Q000097:blood* / Q000502:physiology
chemical_list: D012738:Sex Hormone-Binding Globulin; D015675:Osteocalcin; D013739:Testosterone